TrueSpeech® Co-Processor
PRELIMINARY/CONFIDENTIAL
Version: 1.18
9.20.11 Programming the CT8022 Filters
The Host can program Filter Parameter Sets 0-3 t. The Filter Parameter Set to be programmed is selected by the
CPFID parameter set using the Filter Select command 5154H-5157H.
Each Filter Parameter Set contains 19 words of parameter data.
To start programming of the Filter Parameter Set, use the following command:
Command (515BH):
0101
0001
0101
(7-4)
1011
(15-12)
(11-8)
(3-0)
Status (515BH):
0101
0001
0101
(7-4)
1011
(15-12)
(11-8)
(3-0)
After writing this command, the next 19 words written to the Software Control Register (command register) will be
written to the Filter Set selected.
Command (XXXXH):
Filter Parameter Set Data Word
(15-0)
Status (XXXXH):
Filter Parameter Set Data Word
(15-0)
CT8022 Compatibility Note:
Note that the earlier CT8020A11BQC (firmware revision 0112) only allowed downloading of the first
15 words of the filter parameter set. This was implemented using the 515EH command. The new
515BH command implemented in the CT8022 (firmware revision 0117) and the CT8020D11AQC
(firmware revision 0114) allows downloading of all 19 parameters in the filter parameter set. The
CT8022 continues to support the 515EH command for purposes of backward compatibility with the
older CT8020A11BQC version.
The filter data consists of 15 words of filter coefficients for the sixth order filter (3 x 5 words), plus 4 additional
control parameters.
Each filter is a sixth-order filter constructed from 3 cascaded second-order stages.
138
DSP GROUP, INC., 3120 SCOTT BOULEVARD CT8022A11AQC FW Revision 0118
SANTA CLARA, CA 95054 PH: 408 986 – 4300 FAX: 408 986 – 4490
All specifications are subject to change without prior notice.
ETC [ ETC ]
